Most people think of the Wehrmacht at the time as being some steel and diesel killing machine... People seem to forget that it was literally horsepower, not diesel engines, that moved the army.
The reason why Wehrmacht was as good as it was was because of modern training and awesome commanders, thats pretty much it.
Yeah, electric boats
Everyone had them.
air-independent propulsion
Everyone had it.
turbojet bombers and fighters, rocket-powered fighters
Everyone had the technology, it just was not economic enough to build them, not even for the Germans, see fuel consumption, basically all inventions you listed either existed as counterparts or had been in design stage and not produced for economic reasons.
Assault rifles have been designed and even built decades before WW2, Germans just started mass producing one, they did not invent nor were they the first to field one (Russians or French were).
Or...as the American said to the Soviets after the moon landing: "Our Germans are better than your Germans!"
Silly chauvinist arguments, most german inventions are simply applications of inventions by other nations, paperclip was done for the same reason why Germany drains Polands scientists today, you can never have too few brainiacs, Germany loved to field weirdo projects but thats what they were, other countries had the technology but did not waste resources.
For the cost of one ME262 you could build four mustang fighters and they used less fuel in one mission than that plane.
Stop masturbating about how awesome the german technology was, much of what they had was copied or based on other peoples work.
So, the polish army was badly led and badly equipped.
Just a dose of reality!
However the technology level was the same, its the money that Poland was short on.
